AMD Ryzen and Memory: how fast should my RAM be?

C

c3k

2[H]4U
Joined
Sep 8, 2007
Messages
2,330
Folks,

Between the just-breaking news about the Intel security flaw, a new R6 Define case by Fractal Design (with tempered glass), and the many cool pictures of hardware floating about...I've got the upgrade itch.

I'm leaning (heavily) towards an AMD build. I think a 1700x (or, if the money's there, bumping up to a Threadripper of some flavor) would do, but I am trying to understand the RAM scene.

How important is the speed of Ram for an AMD build these days?

What is the performance difference between 2400Mhz and 3200Mhz? Does the RAM need to a multiple of any of the cpu clocks? Or, if not "need to be", is it better to get specific multiples? Etc.

RAM has gotten pricey and I'd rather get it right the first time.

Any advice would be appreciated.

Thanks.
 
3000 and 3200 have almost identical performance numbers so I would not worry about going beyond that. 2400 ram will lower the performance some on the chip but you can run tighter timings as well and that will boost the performance back up. Really unless your running benchmarks all day or playing games at under 1080p you wont notice much difference at all. If you want to play it safe there is memory sold that is certified for Ryzen use and if you avoid dual rank Ram it will make your life easier if you want higher speeds on the memory.
 
Ryzen benefits a lot from Ram speed but after 2933mhz you hit a point of diminishing returns and after 3200mhz the performance boost takes a real nose dive so no real point in going above it. Up to 2933 you do not have to worry about compatibility as long as you use the latest BIOS, most of them work just fine. 3200 however is problematic because only Samsung chips tend to work where Hynix do not.

So, either buy any 2933 ram with tightest timings you can or buy 3200mhz Gskill Flare X which is guaranteed to work with any mobo without hassle, though it is a bit pricey.
 
I had several memory kits with different Ryzen setups. The Flare X is the only one that ran at rated speeds/timings (Samsung B die). I had a set of Trident Z's that ran at 2933 without issue, but wouldn't run at rated 3400mhz (Samsung E die).

I had some Patriot 2800mhz RAM that wouldn't boot over 2133mhz, but that was on earlier bioses, and I have no idea what ICC's were in it.

I've found this to be helpful when picking Ryzen memory.
 
kirbyrj said:
I had several memory kits with different Ryzen setups. The Flare X is the only one that ran at rated speeds/timings (Samsung B die). I had a set of Trident Z's that ran at 2933 without issue, but wouldn't run at rated 3400mhz (Samsung E die).

I had some Patriot 2800mhz RAM that wouldn't boot over 2133mhz, but that was on earlier bioses, and I have no idea what ICC's were in it.

I've found this to be helpful when picking Ryzen memory.
Click to expand...

Great link! Thanks.
 
Like others have said, try and shoot for 3000MHz-3200MHz. The biggest thing is finding RAM that will run right on a specific motherboard.
 
My Corsair LPX 3000 works at 2933 without issue, though it took a few bios updates to get there. Check the motherboard qvl list for ram and get something on there and it should be good, the qvl list for mine was spot on as they'd update it with almost every bios update and I could run my ram at the speed listed in the qvl table.
 
Nice. I appreciate all the good info.

Now, I just need RAM prices to get reasonable again.
 
I went from 2400 to 3200 with the FlareX kit. I'd say you can expect maybe a 5% gain in gaming (but sometimes less, or no gain, depending on the game).

If you have the money, get AM4 RAM (i.e. FlareX or Fortis) as the compatibility is better at top speed.

In any case, make sure to check the motherboard memory QVL list and see that the exact model number is listed before you buy. If you don't, you may be limited to 2400 or even 2133 speed regardless of how fast the kit is rated for.

And things have improved since the launch of Ryzen, so I wouldn't worry too much, but still do the research to be safe.
 
I just got the Corsair 3200mhz Z kit (CMK16GX4M2Z3200C16) which is supposed to be Ryzen compatible, seems to work great. Passed an hour of GSAT no problem at the XMP setting.
 
yossarian said:
About a month ago I got G.SKILL Ripjaws V Series 16GB (2 x 8GB) 288-Pin DDR4 SDRAM DDR4 3200 (PC4 25600) Desktop Memory Model F4-3200C14D-16GVK at Newegg for $200. It's $220 now, but still over $100 less than the FlareX. It uses the Samsung memory, and it runs at 3200 with XMP in my Asrock x370 Tiachi and 1800x I built last week. They have CAS 15 at $193 on sale, I assume it's also Samsung memory.
Click to expand...

I go at similar kit F4-3200C16-8GVGB its samsung D or E die and runs XMP 3200 just fine on my prime x370 pro with latest bios. so you don't need B die for 3200 .
 
Really anything past 2400mhz isn't very noticeable, mostly in theoretical Benches. That Route up to 3200mhz should be absolutely plenty and monster.
 
My experience has been that D or E die only run up to 2933mhz (Asus board). If it's 3200mhz and Cas 14, it's probably B die though. If it's Cas 16 or something like that, it's probably something else.

This link has good info.
 
kirbyrj said:
My experience has been that D or E die only run up to 2933mhz (Asus board). If it's 3200mhz and Cas 14, it's probably B die though. If it's Cas 16 or something like that, it's probably something else.

This link has good info.
Click to expand...

I have the
F4-3200C16Q-64GVK with 64GB on the Asus Crosshair VI I have capped out at 2800mhz.
 
yeah with 4 or 8GB sticks cas 16 is 99% of the time hynix.. i think corsairs the only one that uses samsung B or tuned samsung D/E in their LPX cas 16 ram. gskill and everyone else uses hynix.. cas 15 can be either samsung B, D, E, or hynix. cas 14 3200+ is primarily samsung B.


Vader1975 said:
I have the
F4-3200C16Q-64GVK with 64GB on the Asus Crosshair VI I have capped out at 2800mhz.
Click to expand...

sounds about right since it's double rank and using all 4 DDR4 lanes which is a whole different issue besides the ram modules used.
 
Last edited:
Vader1975 said:
I have the
F4-3200C16Q-64GVK with 64GB on the Asus Crosshair VI I have capped out at 2800mhz.
Click to expand...

I should have been more specific. I was talking about 8GB dimms. 16GB dimms are too rich for my blood at this point ;).
 
Does ram speed have a effect on the ammount you have?For example see people using 32gb and 64gb runing at the desired 3000mhz.But than in a few forums i saw workstations with 128gb and they run with 2400/2666 mhz.So for a stable 1950x machine with 128gb coud we have the ram set to 3000mhz or is it just too much because of the huge amount?
 
The Ryzen's cap out at 64GB and yes the higher the volume the lower the stability on the platform. I have seen many people with 4000+ 16GB kits and 3200+ on 32GB kits. I have even seen very specific 64gb kits reach 3200mhz. However how stable they truly are over time is in question. My kit definitely isn't optimal but I usually see people fail to reach 2900 mhz at 64GB.
 
Vader1975 said:
The Ryzen's cap out at 64GB and yes the higher the volume the lower the stability on the platform. I have seen many people with 4000+ 16GB kits and 3200+ on 32GB kits. I have even seen very specific 64gb kits reach 3200mhz. However how stable they truly are over time is in question. My kit definitely isn't optimal but I usually see people fail to reach 2900 mhz at 64GB.
Click to expand...
Thanks.
I can only hope that threadripper 2 will be compatible with existing x399 motherboards and resolves this.
 
The Threadripper setup is designed for ECC memory, but I have seen a number of users putting 64GB of DDR4 on the platform. Some have even reached 3200mhz on it. When I see people start saying 3600mhz or higher, I find them using less and less total ram.
 
The safe bet for buying performance ryzen or TR ram and getting that sweet boost from fabric speed is more or less established as:

3200 C14 (14-14-14, no fake 14-16-16 shit)
3600 C16 (16-16-16, no fake 16-18-18 shit)

Which last I checked also means don't even bother trying to buy corsair and be happy with 32GB max.

These modules are basically the same thing and will be samsung B die. They will probably be gskill as well ;)

Higher speeds are a wash but either of these modules will run 3200 C14 1.35V using 2 or 4 dimm with recent agesa updates. The 3600 is slightly more work because it has prebuilt extra 3466 and 3400 profiles yet no 3200, but you can steal the 3200 timings just fine. I would try and boot at 3600 at least once for luck though.
Going from 4 to 8 dimms on TR (2DPC) is a huge hit on your stability and/or success rate. Going from 2 to 4 dimms on AM4 (2DPC) doesn't seem to matter for single-rank.

PS: don't obsess over single vs dual rank performance boost, fabric performance boost trumps it hard.
 
You must log in or register to reply here.
Back
Top